#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
using namespace std;

const int N = 1e4 + 10, INF = 0x3f3f3f3f;

int n, m;
vector<int> g[N];
int st[100010], tt;

void dfs(int x)
{
    while (g[x].size()) {
        int y = g[x].back();g[x].pop_back();
        dfs(y);
    }
    st[++tt] = x;
}

void solve()
{
    cin >> n >> m;
    for (int i = 1;i <= m;i++) {
        int x, y;cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    dfs(1);
    for (int i = tt;i >= 1;i--)
        cout << st[i] << '\n';
}

signed main()
{
    //ios::sync_with_stdio(0);
    //cin.tie(0);cout.tie(0);
#define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    std::istringstream in(R"()");
    std::cin.rdbuf(in.rdbuf());
#endif
    int T = 1;
    //cin>>T;
    for (int i = 1;i <= T;i++) {
        solve();
    }
}